Even if you decided to re-invent all your UNIX scripts and tools
    on PowerShell, you'd be missing most of the composable tools
    that make UNIX what it is.

PowerShell's composability is based on piping objects rather than piping text.

Do you mean that PowerShell can't achieve the same composability that can be achieved on Unix, or that PowerShell lacks for example `cut`?

To be honest: no, PowerShell can't (practically) achieve the same composability that can be achieved on Windows. Both because of the aforementioned general malaise of writing it throwing up very real roadblocks, but also because not everything under the sun is a .NET application. You get "hack together a text pipeline and hope all your objects implement ToString in a meaningful way" or "break out Visual Studio and write some converters", which is, by my lights, significantly worse than just "hey, everything starts and ends as a stream of bytes, deal with it using the tools we know you have and work with every application you're going to use."

And this is especially egregious with the lack of a Swiss-army-chainsaw scripting language in .NET to begin with.

> To be honest: no, PowerShell can't (practically) achieve the same composability

PowerShell is much more composable. Just consider how all nix commands must pack insane numbers of output options. In PowerShell - just because of composability - output formatting is not the responsibility of each command - it has been delegated to a small set of general-purpose output format cmdlets.